Special equipment: wooden skewers
Preheat the oven to 450 degrees F.
For the tomato sauce: In a saucepan over medium heat, add the olive oil and grated onion and saute until the onion is soft, about 3 minutes. Add the garlic, oregano, 1/2 teaspoon salt and 1/4 teaspoon pepper and saute for 1 minute. Add the crushed tomatoes and tomato paste and stir well. Bring to a boil, then reduce the heat to medium low and simmer for 10 to 12 minutes.
To finish the tomato sauce, remove it from the heat and stir in the extra-virgin olive oil, 1/2 teaspoon salt and 1/4 teaspoon pepper.
For the chicken parmesan: Meanwhile, generously spray a baking sheet with olive oil cooking spray.
In a shallow bowl, mix together the flour, onion powder, 1/2 teaspoon salt and 1/4 teaspoon pepper. In another shallow bowl, whisk together the eggs, 1/2 teaspoon salt and 1/4 teaspoon pepper. In a third shallow bowl, add the panko and crush it a bit with your hands to make it easier for the coating to stick. Measure out 1/4 cup of the shredded mozzarella, chop it finely and add it to the panko with the Parmesan and parsley and toss to combine.
Make an assembly line: coat the chicken strips first in the flour mixture, then shake. Dip next in the egg mixture, then shake. Finish in the panko-cheese mixture. Set the chicken strips on the prepared baking sheet an inch apart from each other.
Bake for 3 minutes, then remove the baking sheet from the oven and flip over the chicken strips. Top with the remaining 3/4 cup shredded mozzarella, then finish baking until cooked through, another 3 to 4 minutes.
Carefully insert a wooden skewer into each chicken strip and serve with the tomato sauce on the side.